Dual panel-type organic electroluminescent display device and method of fabricating the same

ABSTRACT

An organic electroluminescent display device includes first and second substrates bonded together, the first and second substrates having a plurality of pixel regions, each pixel region includes a central portion and first and second portions at both sides of the central portion, a driving element on an inner surface of the first substrate within each of the plurality of pixel regions, the driving element being disposed in the central portion, first and second connection electrodes contacting the driving element and disposed in the first and second portions, a first electrode on an inner surface of the second substrate, an organic electroluminescent layer on the first electrode, and a second electrode on the organic electroluminescent layer, the second electrode contacting the first and second connection electrodes.

The present invention claims the benefit of Korean Patent ApplicationNo. 2002-70299 filed in Korea on Nov. 13, 2002, which is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an organic electroluminescent displaydevice and a method of fabricating an organic electroluminescent displaydevice, and more particularly, to a dual panel-type organicelectroluminescent display device and a method of fabricating a dualpanel-type organic electroluminescent display device.

2. Discussion of the Related Art

In general, organic electroluminescent display (OELD) devices have anelectron-input electrode, which is commonly referred to as a cathode,and hole-input electrode, which is commonly referred to as an anode. Theelectrons and the holes are supplied to an electroluminescent layer fromthe cathode and anode, respectively, wherein the electron and holetogether form an exciton. The OELD device emits light when the excitonis reduced from an excited state level to a ground state level.Accordingly, since the OELD devices do not require additional lightsources, both volume and weight of the OELD devices may be reduced. Inaddition, the OELD devices are advantageous because of their low powerconsumption, high luminance, fast response time, and low weight.Presently, the OELD devices are commonly implemented in mobiletelecommunication terminals, car navigation systems (CNSs), personaldigital assistants (PDAs), camcorders, and palm computers. In addition,since manufacturing processes for the OELD devices are simple,manufacturing costs can be reduced as compared to liquid crystal display(LCD) devices.

The OELD devices may be classified into passive matrix-type and activematrix-type. Although the passive matrix-type OELD devices have simplestructures and simplified manufacturing processes, they require highpower consumption and are not suitable for large-sized display devices.In addition, aperture ratios decrease as the number of electro linesincrease. On the other hand, the active matrix-type OELD devices havehigh light-emitting efficiency and high image display quality.

FIG. 1 is a cross sectional view of an OELD device according to therelated art. In FIG. 1, the OELD device 10 has a transparent firstsubstrate 12, a thin film transistor array part 14, a first electrode16, an organic electroluminescent layer 18, and a second electrode 20,wherein the thin film transistor array part 14 is formed on thetransparent first substrate 12. The first electrode 16, organicelectroluminescent layer 18, and second electrode 20 are formed over thethin film transistor array part 14. The electroluminescent layer 18emits red (R), green (G), and blue (B) colored light, and it is commonlyformed by patterning organic material separately in each pixel region“P” for the R, G, and B colored light. A second substrate 28 has amoisture absorbent desiccant 22. The OELD device 10 is completed bybonding the first and second substrates 12 and 28 together by disposinga sealant 26 between the first and second substrates 12 and 28. Themoisture absorbent desiccant 22 removes moisture and oxygen that may beinfiltrated into an interior of the organic ELD 10. The moistureabsorbent desiccant 22 is formed by etching away a portion of the secondsubstrate 28, filling the etched portion of the second substrate 28 withmoisture absorbent desiccant material, and fixing the moisture absorbentdesiccant material with a tape 25.

FIG. 2 is a plan view of a thin film transistor array part of an OELDdevice according to the related art. In FIG. 2, each of a plurality ofpixel regions “P” defined on a substrate 12 includes a switching element“T_(S),” a driving element “T_(D),” and a storage capacitor “C_(ST).”The switching element “T_(S)” and the driving element “T_(D)” may beformed with combinations of more than two thin film transistors (TFTs),and the substrate 12 is formed of a transparent material, such as glassand plastic. A gate line 32 is formed along a first direction, and adata line 34 is formed along a second direction perpendicular to thefirst direction, wherein the data line 34 crosses the gate lineperpendicularly with an insulating layer between the gate and data lines32 and 34. In addition, a power line 35 is formed along the seconddirection, and is spaced apart from the data line 34.

The TFT used for the switching element “T_(S)” has a switching gateelectrode 36, a switching active layer 40, a switching source electrode46, and a switching drain electrode 50. The TFT for the driving element“T_(D)” has a driving gate electrode 38, a driving active layer 42, adriving source electrode 48, and a driving drain electrode 52. Theswitching gate electrode 36 is electrically connected to the gate line32, and the switching source electrode 46 is electrically connected tothe data line 34. In addition, the switching drain electrode 50 iselectrically connected to the driving gate electrode 38 through acontact hole 54, and the driving source electrode 48 is electricallyconnected to the power line 35 through a contact hole 56. Further, thedriving drain electrode 52 is electrically connected to a firstelectrode 16 within the pixel region “P,” wherein the power line 35 anda first capacitor electrode 15 that is formed of polycrystalline siliconlayer form a storage capacitor “C_(ST)”.

FIG. 3 is a cross sectional view along III—III of FIG. 2 according tothe related art. In FIG. 3, a first insulating layer (i.e., a bufferlayer) 14 is formed on a substrate 12, and a driving element, (i.e., adriving thin film transistor TFT) “T_(D)” including an active layer 42,a gate electrode 38, and source and drain electrodes 48 and 52 is formedon the first insulating layer 14. The active layer 42 is formed on thefirst insulating layer 14 and a second insulating layer (a gateinsulating layer) 37 is interposed between the active layer 42 and thegate electrode 38. In addition, third and fourth insulating layers 39and 41 are interposed between the gate electrode 38 and the source anddrain electrodes 48 and 52. Further, a power line 35 is formed betweenthe third and fourth insulating layers 39 and 41, and connected to thesource electrode 48.

A first electrode 16 is formed over the driving TFT “T_(D)” and isconnected to the drain electrode 52 of the driving TFT “T_(D)” with afifth insulating layer 57 between the first electrode 16 and the drivingTFT “T_(D).” An organic electroluminescent (EL) layer 18 is formed onthe first electrode 16 for emitting light of a particular colorwavelength, and a second electrode 20 is formed on the organic EL layer18. Accordingly, after forming a sixth insulating layer 58 on the firstelectrode 16, the sixth insulating layer 58 is patterned to expose thefirst electrode 16. Then, the organic EL layer 18 and the secondelectrode 20 are sequentially formed on the exposed first electrode 16,and a storage capacitor “C_(ST)” is connected in parallel to the drivingTFT “T_(D),” and includes first and second capacitor electrodes 15 and35. The source electrode 48 contacts the second capacitor electrode 35(i.e., a power line), and the first capacitor electrode 15 is formed ofpolycrystalline silicon material under the second capacitor electrode35. Moreover, the second electrode 20 is formed on an entire surface ofthe substrate 12 on which the driving TFT “T_(D),” the storage capacitor“C_(ST),” and the organic electroluminescent layer 18 are formed.

In the OELD device, a TFT array part and an organic electroluminescentdiode are formed over a first substrate, and an additional secondsubstrate is attached with the first substrate for encapsulation.However, when the array part and the organic EL diode are formed on onesubstrate, a production yield of the organic ELD is determined by amultiplication of TFT's yield and organic emission layer's yield. Sincethe yield of the organic emission layer is relatively low, theproduction yield of an ELD is limited by the yield of the organic layer.For example, even when a TFT is properly fabricated, an OELD deviceusing a thin film of about 1000 Å thickness can be determined to beunacceptable due to defects of the organic emission layer. Accordingly,the loss of materials causes an increase in production costs.

In general, OELD device are classified into bottom emission-type and topemission-type according to an emission direction of light used fordisplaying images. Bottom emission-type OELD devices have the advantagesof high encapsulation stability and high process flexibility. However,the bottom emission-type OELD devices are ineffective for highresolution devices because they have poor aperture ratios. In contrast,the top emission-type OELD devices have a higher expected life spanbecause they are easily designed and have a high aperture ratio.However, in the top emission-type OELD devices, the cathode is generallyformed on an organic emission layer. As a result, transmittance andoptical efficiency of the top emission-type OELD devices are reducedbecause of a limited number of materials that may be selected. If a thinfilm-type passivation layer is formed to prevent a reduction of thelight transmittance, the thin film-type passivation layer may fail toprevent infiltration of exterior air into the device.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an OELD device and amethod of fabricating an OELD that substantially obviate one or more ofthe problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a dual panel-type OELDdevice that is fabricated through forming array elements and organicelectroluminescent diodes on respective substrates and attaching therespective substrates.

Another object of the present invention is to provide a method offabricating a dual panel-type OELD device that is fabricated throughforming array elements and organic electroluminescent diodes onrespective substrates and attaching the respective substrates.

Another object of the present invention is to provide an OELD devicehaving improved production yield, high brightness, and high apertureratio.

Another object of the present invention is to provide a method offabricating an OELD device having improved production yield, highbrightness, and high aperture ratio.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, an organicelectroluminescent display device includes first and second substratesbonded together, the first and second substrates having a plurality ofpixel regions, each pixel region includes a central portion and firstand second portions at both sides of the central portion, a drivingelement on an inner surface of the first substrate within each of theplurality of pixel regions, the driving element being disposed in thecentral portion, first and second connection electrodes contacting thedriving element and disposed in the first and second portions, a firstelectrode on an inner surface of the second substrate, an organicelectroluminescent layer on the first electrode, and a second electrodeon the organic electroluminescent layer, the second electrode contactingthe first and second connection electrodes.

In another aspect, a method of fabricating an organic electroluminescentdisplay device includes forming a driving element on a first substratehaving a plurality of pixel regions, each pixel region including acentral portion and first and second portions at both sides of thecentral portion, the driving element being disposed in the centralportion, forming first and second connection electrodes contacting thedriving element, the first and second connection electrodes beingrespectively disposed in the first and second portions, forming a firstelectrode on a second substrate, forming an organic electroluminescentlayer on the first electrode, forming a second electrode on the organicelectroluminescent layer, and bonding the first and second substratestogether such that the second electrode contacts the first and secondconnection electrodes.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a cross sectional view of an OELD device according to therelated art;

FIG. 2 is a plan view of a thin film transistor array part of an OELDdevice according to the related art;

FIG. 3 is a cross sectional view along III—III of FIG. 2 according tothe related art;

FIG. 4 is a schematic cross-sectional view of an exemplary OELD deviceaccording to the present invention;

FIG. 5 is a schematic plan view of an exemplary thin film transistorarray part of an OELD device according to the present invention;

FIGS. 6A to 6D are schematic cross sectional views along VI—VI of FIG. 5of an exemplary method of fabricating a thin film transistor array partof an organic electroluminescent device according to the presentinvention;

FIGS. 7A to 7D are schematic cross sectional views along VII—VII of FIG.5 of another exemplary method of fabricating a thin film transistorarray part of an organic electroluminescent device according to thepresent invention; and

FIGS. 8A to 8C are schematic cross sectional views of another exemplarymethod of fabricating an organic electroluminescent diode of an organicelectroluminescent device according to the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 4 is a schematic cross-sectional view of an exemplary OELD deviceaccording to the present invention. In FIG. 4, an OELD device 99 mayinclude first and second substrates 100 and 200 facing each other, andbonded together with a sealant 300. The first and second substrates 100and 200 may include a plurality of pixel regions “P,” switching anddriving thin film transistors (TFTs) “T,” and array lines (not shown)formed on an inner surface of the first substrate 100 within each of thepixel regions “P.” Although not shown, the array lines may include agate line, a data line, a power line, and a common line.

In FIG. 4, a first electrode 202 may be formed on an inner surface ofthe second substrate 200, and an organic electroluminescent (EL) layer208 emitting one of red, green, and blue colored lights may be formed onthe first electrode 202 within each of the pixel regions “P.” Inaddition, a second electrode 210 may be formed on the organic EL layer208 within each of the pixel regions “P.” The organic EL layer 208 mayinclude a single layer structure or may include a multiple layerstructure. The multiple layer structure may include the organic EL layer208 having a hole-transporting layer 208 b on the first electrode 202,an emission layer 208 a on the hole-transporting layer 208 b, and anelectron-transporting layer 208 c on the emission layer 208 a.

The pixel regions “P” may each include a central portion “C” and firstand second portions “D1” and “D2” surrounding the central portion “C,”wherein the driving TFT “T” may be formed in the central portion “C.” Inaddition, first and second connection electrodes 128 a and 128 b may beformed in the first and second portions “D1” and “D2,” respectively,wherein the first and second connection electrodes 128 a and 128 b maybe connected to the second electrode 210. The first and secondconnection electrodes 128 a and 128 b may be formed on the driving TFT“T” during a fabricating process of the first substrate 100, or thefirst and second connection electrodes 128 a and 128 b may be formed onthe second electrode 210 during a fabricating process of the secondsubstrate 200. After bonding the first and second substrates 100 and 200together, the driving TFT “T” and the second electrode 210 may beconnected to each other through the first and second connectionelectrodes 128 a and 128 b.

FIG. 5 is a schematic plan view of an exemplary thin film transistorarray part of an OELD device according to the present invention. In FIG.5, a gate line 103, a data line 115, and a power line 114 may be formedon a first substrate 100, wherein the data line 115 and the power line114 may cross the gate line 103 to define a pixel region “P.” A drivingthin film transistor (TFT) “T_(D),” a switching thin film transistor(TFT) “T_(ST),” and a storage capacitor “C_(ST)” may be formed withinthe pixel region “P.” The driving TFT “T_(D)” may include a drivingactive layer 104, a driving gate electrode 110, and driving source anddrain electrodes 126 and 125, and the switching TFT “T_(ST)” may includea switching active layer 106, a switching gate electrode 111, andswitching source and drain electrodes 121 and 123. The storage capacitor“C_(ST)” may be connected in parallel to the driving TFT “T_(D),” andmay use an active pattern 107 of polycrystalline silicon as a firstcapacitor electrode and the power line 114 as a second capacitorelectrode. The switching source electrode 121 may be connected to thedata line 115, and the switching drain electrode 123 may be connected tothe driving gate electrode 110.

The driving TFT “T_(D)” may be formed at a central portion of the pixelregion “P.” Accordingly, the driving gate electrode 110 may extend tothe switching TFT “T_(ST)” and may contact the switching drain electrode123. The driving drain electrode 125 may include first and secondextensions 125 a and 125 b, and the pixel region “P” may be divided intofirst and second portions with the central portion having the drivingTFT “T_(D)” as a center. The first and second extensions 125 a and 125 bmay be formed in the first and second portions, respectively. Althoughnot shown, the first and second extensions 125 a and 125 b may contactthe first and second connection electrodes 128 a and 128 b (in FIG. 4),respectively.

FIGS. 6A to 6D and are schematic cross sectional views along VI—VI ofFIG. 5 of an exemplary method of fabricating a thin film transistorarray part of an organic electroluminescent device according to thepresent invention, and FIGS. 7A to 7D are schematic cross sectionalviews along VII—VII of FIG. 5 of another exemplary method of fabricatinga thin film transistor array part of an organic electroluminescentdevice according to the present invention.

In FIGS. 6A and 7A, a first insulating layer (i.e., a buffer layer) 102may be formed on a first substrate 100 having a pixel region “P” bydepositing one of inorganic insulating material(s), such as siliconnitride (SiN_(x)) and silicon oxide (SiO₂). The pixel region “P” may bedivided into a central portion “C,” and first and second portions “D1”and “D2” at both sides of the central portion “C,” wherein a drivingthin film transistor “T_(D)” and a storage capacitor “C_(ST)” may bedisposed in the central portion “C.”

Then, an amorphous silicon (a-Si:H) layer (not shown) may be formed onthe first insulating layer 102, and crystallized to form apolycrystalline silicon layer (not shown). Next, a driving active layer104 including a channel region 104 a, and source and drain regions 104 band 104 c at both sides of the channel region 104 a may be formed bypatterning the polycrystalline silicon layer. At the same time, anactive pattern 107 used as a first capacitor electrode may be formed onthe first insulating layer 102. Alternatively, a dehydrogenation processmay be performed before the crystallization process, and thecrystallization process can be performed by using heat or light.

Next, a second insulating layer (i.e., a gate insulating layer) 108 maybe formed on the driving active layer 104 by depositing inorganicinsulating material(s), such as silicon nitride (SiN_(x)) and siliconoxide (SiO₂). The second insulating layer 108 may be formed on an entiresurface of the first substrate 100 without any subsequent etch process,or may be etched to have the same shape as a driving gate electrode 110after forming the driving gate electrode 110.

Next, a driving gate electrode 110 may be formed on the secondinsulating layer 108 over the channel region 104 a, and as shown in FIG.5, the driving gate electrode 110 may extend to a switching TFT“T_(ST).” Then, the source and drain regions 104 b and 104 c of theactive layer 104 may be doped with impurities, such as boron (B) orphosphorous (P). The driving gate electrode 110 may include conductivemetallic material(s), such as aluminum (Al), an aluminum (Al) alloy,copper (Cu), tungsten (W), tantalum (Ta), and molybdenum (Mo).

Next, a third insulating layer (i.e., an interlayer insulating layer)112 may be formed on the driving gate electrode 110, and a power line114 may be formed on the third insulating layer 112. The power line 114may supply signals to a driving drain electrode (not shown) and may beused as a second capacitor electrode.

In FIGS. 6B and 7B, a fourth insulating layer (i.e., a passivationlayer) 116 may be formed on the power line 114 by depositing inorganicinsulating material(s), such as silicon nitride (SiN_(x)) and siliconoxide (SiO₂), or organic insulating material(s), such asbenzocyclobutene (BCB) and acrylic resin. The fourth insulating layer116 may include first, second, and third contact holes 120, 118, and 122to expose the source region 104 b, the drain region 104 c, and the powerline 114, respectively. Although not shown, a switching active layer maybe simultaneously exposed.

In FIGS. 6C and 7C, driving source and drain electrode 126 and 125 maybe formed on the fourth insulating layer 116 by depositing andpatterning conductive metallic material(s), such as aluminum (Al), analuminum (Al) alloy, chromium (Cr), tungsten (W), and molybdenum (Mo).The driving drain electrode 125 may be connected to the drain region 104c through the first contact hole 118 and may extend to the first andsecond portions “D1” and “D2.” The source electrode 126 may be connectedto the source region 104 b through the second contact hole 120 and maybe connected to the power line 114 through the third contact hole 122.Although not shown, switching source and drain electrodes and a dataline 115 (in FIG. 5) may be simultaneously formed over the switchingactive layer. The switching source electrode may be connected to thedata line 115 (in FIG. 5) parallel to the power line 114, and theswitching drain electrode may be connected to the driving gate electrode110. In addition, the driving drain electrode 125 may include first andsecond extensions 125 a and 125 b disposed in the first and secondportions “D1” and “D2” of the pixel regions “P,” respectively, whereinthe first and second extensions 125 a and 125 b may be formed to havevarious shapes.

In FIGS. 6D and 7D, a fifth insulating layer 130 having first and secondopen portions 132 a and 132 b may be formed on the driving source anddrain electrodes 126 and 125 by depositing organic insulatingmaterial(s), such as benzocyclobutene (BCB) and acrylic resin. The firstand second open portions 132 a and 132 b may expose the first and secondextensions 125 a and 125 b of the driving drain electrode 125,respectively. In addition, first and second connection electrodes 128 aand 128 b may be formed on the first and second extensions 125 a and 125b, respectively, wherein the first and second connection electrodes 128a and 128 b may contact a second electrode 210 (in FIG. 4) after bondingthe first and second substrates 100 and 200 (in FIG. 4) together.Accordingly, the first and second connection electrodes 128 a and 128 bmay include the same material as the second electrode 210 (in FIG. 4).Alternatively, the fifth insulating layer 130 may be omitted.

In the present invention, a driving TFT may be disposed in a centralportion of a pixel region. In addition, first and second connectionelectrodes may be disposed in first and second portions at both sides ofthe central portion, respectively. Accordingly, a connection portionbetween a second electrode and a driving drain electrode may beenlarged. Moreover, since the connection portion may include two parts(first and second connection electrodes), connection inferiority due toa substrate warpage may be prevented.

FIGS. 8A to 8C are schematic cross sectional views of another exemplarymethod of fabricating an organic electroluminescent diode of an organicelectroluminescent device according to the present invention. In FIG.8A, a first electrode 202 may be formed on a second substrate 200 havinga plurality of pixel regions “P.” The first electrode 202 may includetransparent conductive metallic material(s), such as indium-tin-oxide(ITO) and indium-zinc-oxide (IZO).

In FIG. 8B, an organic electroluminescent (EL) layer 204 emitting one ofred (R), green (G), and blue (B) colored lights may be formed on thefirst electrode 202 within each of the pixel regions “P.” The organic ELlayer 204 may have a single layer structure or a multiple layerstructure. In the multiple layer structure, the organic EL layer 204 mayhaving a hole-transporting layer 204 b on the first electrode 202, anemission layer 204 a on the hole-transporting layer 204 b, and anelectron-transporting layer 204 c on the emission layer 204 a.

In FIG. 8C, a second electrode 210 may be formed on the organic EL layer204 within each of the pixel regions “P.” The second electrode 210 mayinclude a single layer structure including at least one of aluminum(Al), calcium (Ca), and magnesium (Mg), for example, or may have amultiple layer structure including lithium fluorine/aluminum (LiF/Al),for example.

Next, an OELD device may be obtained by bonding the first and secondsubstrates 100 and 200 fabricated through processes of FIGS. 6A to 8Ctogether.

An OELD device according to the present invention is advantageous sincea connection portion may include two parts (first and second connectionelectrodes) disposed in first and second portions at both sides of acentral portion of a pixel region. Accordingly, the connection portionmay be enlarged and a connection inferiority due to a substrate warpagemay be prevented, thereby obtaining a highly reliable device.

In addition, since the OELD device is a top emission-type OELD device, athin film transistor may be easily designed, and high resolution andhigh aperture ratio may be obtained regardless of lower array patterns.Furthermore, since array patterns and an organic EL diode may be formedon respective substrates, production yield and production managementefficiency are improved, and a lifetime of an organic EL device islengthened.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the organicelectroluminescent device and fabricating method thereof of the presentinvention without departing from the spirit or scope of the invention.Thus, it is intended that the present invention cover the modificationsand variations of this invention provided they come within the scope ofthe appended claims and their equivalents.

1. An organic electroluminescent display device, comprising: first andsecond substrates bonded together, the first and second substrateshaving a plurality of pixel regions, each pixel region includes acentral portion and first and second portions at both sides of thecentral portion; a driving element on an inner surface of the firstsubstrate within each of the plurality of pixel regions, the drivingelement being disposed in the central portion; first and secondconnection electrodes contacting the driving element and disposed in thefirst and second portions; a first electrode on an inner surface of thesecond substrate; an organic electroluminescent layer on the firstelectrode; and a second electrode on the organic electroluminescentlayer, wherein the second electrode contacts the first and secondconnection electrodes.
 2. The device according to claim 1, wherein thedriving element includes a thin film transistor having a driving activelayer, a driving gate electrode, a driving source electrode, and adriving drain electrode.
 3. The device according to claim 2, wherein thedriving drain electrode includes a first extension in the first portionand a second extension in the second portion.
 4. The device according toclaim 3, wherein the first and second connection electrodes contact thefirst and second extensions, respectively.
 5. The device according toclaim 1, further comprising a switching element connected to the drivingelement via a capacitor.
 6. The device according to claim 5, wherein theswitching element includes a gate electrode connected to a gate line, asource connected to a data line, and a drain connected to a firstelectrode of the capacitor.
 7. The device according to claim 6, whereinthe driving element includes a source connected to a second electrode ofthe capacitor.
 8. The device according to claim 6, wherein the drain ofthe switching element is connected to a gate of the driving element. 9.The device according to claim 1, wherein the first electrode is an anodefor injecting holes into the organic electroluminescent layer and thesecond electrode is a cathode for injecting electrons into the organicelectroluminescent layer.
 10. The device according to claim 9, whereinthe first electrode includes one of indium-tin-oxide (ITO) andindium-zinc-oxide (IZO).
 11. The device according to claim 9, whereinthe second electrode includes at least one of aluminum (Al), calcium(Ca), magnesium (Mg), and lithium (Li).
 12. The device according toclaim 1, wherein the organic electroluminescent layer includes ahole-transporting layer and an electron-transporting layer.
 13. A methodof fabricating an organic electroluminescent display device, comprising:forming a driving element on a first substrate having a plurality ofpixel regions, each pixel region including a central portion and firstand second portions at both sides of the central portion, the drivingelement being disposed in the central portion; forming first and secondconnection electrodes contacting the driving element, the first andsecond connection electrodes being respectively disposed in the firstand second portions; forming a first electrode on a second substrate;forming an organic electroluminescent layer on the first electrode;forming a second electrode on the organic electroluminescent layer; andbonding the first and second substrates together such that the secondelectrode contacts the first and second connection electrodes.
 14. Themethod according to claim 13, wherein forming of the driving elementincludes forming a driving active layer, forming a driving gateelectrode, and forming driving source and drain electrodes.
 15. Themethod according to claim 14, wherein the driving drain electrodeincludes a first extension in the first portion and a second extensionin the second portion.
 16. The method according to claim 15, wherein thefirst and second connection electrodes contact the first and secondextensions, respectively.
 17. The method according to claim 13, furthercomprising forming a switching element connected to the driving element.18. The method according to claim 13, wherein the first electrode is ananode for injecting holes into the organic electroluminescent layer andthe second electrode is a cathode for injecting electrons into theorganic electroluminescent layer.
 19. The method according to claim 18,wherein the first electrode includes one of indium-tin-oxide (ITO) andindium-zinc-oxide (IZO).
 20. The device according to claim 18, whereinthe second electrode includes at least one of aluminum (Al), calcium(Ca), magnesium (Mg), and lithium (Li).
 21. The method according toclaim 13, wherein the organic electroluminescent layer includes ahole-transporting layer and an electron-transporting layer.